The invention relates to a hand-held laser bar code reader, or scanner, and to the meeting of safety requirements in regard to such laser devices.
Scanners for reading bar codes have been increasingly used for commercial and industrial purposes. In addition to the well-known use in supermarkets for reading the labels on goods they are also used in warehouses for inventory and identification of goods. However, in warehouse usage there is often a considerable distance to the goods. For this purpose there is in general a need for hand-held scanners that can read over a long distance for making the work of the user more efficient and to avoid the need for climbing up to goods stored in high places.
At the same time, such scanners must satisfy safety requirements, such as those promulgated by regulations such as 21 CFR .sctn.1040 in the United States and I.E.C. Pub. 825, of the International Electrotechnical Commission. These requirements specify that a laser scanner (depending on use) must be of sufficiently low power that its beam will not injure the human eye if aimed directly into the eye for a prescribed period of time (often 1000 seconds, or about 16 minutes.)
It is an object of the present invention to produce a relatively high powered hand-held laser bar code reader, suitable for efficient use in warehouses and like places, which includes a safety device to prevent the possibility of beam exposure to the human eye for dangerous periods.